[LyX/master] Do not require esint for \int (bug 9498)

[Georg Baum]

commit 08b285966326523a10954cf6235d0c7b200c842f
Author: Georg Baum <b...@lyx.org>
Date:   Sat May 16 12:29:54 2015 +0200

    Do not require esint for \int (bug 9498)
    
    We also get a consistent look with amsmath, so require esint or amsmath.
    When resolving alternatives, do also take into account whether the package
    is available. For this to work, we also need to test for amsmath.sty (which
    was surprisingly not yet done).

diff --git a/lib/chkconfig.ltx b/lib/chkconfig.ltx
index e8cb027..9c1c2f6 100644
--- a/lib/chkconfig.ltx
+++ b/lib/chkconfig.ltx
@@ -272,6 +272,7 @@
 \TestPackage{achicago}
 \TestPackage{algorithm}
 \TestPackage{algorithm2e}
+\TestPackage{amsmath}
 \TestPackage{amstext}
 \TestPackage{apacite}
 \TestPackage{apalike}
diff --git a/lib/symbols b/lib/symbols
index cbd8307..89fc41a 100644
--- a/lib/symbols
+++ b/lib/symbols
@@ -995,7 +995,7 @@ tbond              cmsy        180 186 mathord  x
 # If the wasysym integrals are really wanted then one has to load the package
 # manually and disable automatic loading of amsmath and esint.
 iffont esint
-int                esint        001    0  mathop  &int;         esint
+int                esint        001    0  mathop  &int;         esint|amsmath
 intop              esint        001    0  mathop  &int;         esint
 iint               esint        003    0  mathop  &Int;         esint|amsmath
 iintop             esint        003    0  mathop  &Int;         esint
@@ -1021,7 +1021,7 @@ ointctrclockwiseop esint        023    0  mathop  
&awconint;    esint
 ointclockwise      esint        025    0  mathop  &cwconint;    esint
 ointclockwiseop    esint        025    0  mathop  &cwconint;    esint
 else
-int                cmex          82  242  mathop  &int;         esint
+int                cmex          82  242  mathop  &int;         esint|amsmath
 intop              cmex          82  242  mathop  &int;         esint
 iint               wasy         115    0  mathop  &Int;         esint|amsmath
 iintop             wasy         115    0  mathop  &Int          esint
diff --git a/src/LaTeXFeatures.cpp b/src/LaTeXFeatures.cpp
index dcfb44c..b4da005 100644
--- a/src/LaTeXFeatures.cpp
+++ b/src/LaTeXFeatures.cpp
@@ -1756,10 +1756,23 @@ void LaTeXFeatures::resolveAlternatives()
                        vector<string> const alternatives = 
getVectorFromString(*it, "|");
                        vector<string>::const_iterator const end = 
alternatives.end();
                        vector<string>::const_iterator ita = 
alternatives.begin();
+                       // Is any alternative already required? => use that
                        for (; ita != end; ++ita) {
                                if (isRequired(*ita))
                                        break;
                        }
+                       // Is any alternative available? => use the first one
+                       // (bug 9498)
+                       if (ita == end) {
+                               for (ita = alternatives.begin(); ita != end; 
++ita) {
+                                       if (isAvailable(*ita)) {
+                                               require(*ita);
+                                               break;
+                                       }
+                               }
+                       }
+                       // This will not work, but not requiring something
+                       // would be more confusing
                        if (ita == end)
                                require(alternatives.front());
                        features_.erase(it);